// test rand()
//
#include <stdio.h>
#include <math.h>
#include <stdlib.h> // rand(), srand(), RAND_MAX
#include <time.h>

int main( void)
{
  int t = time(0); // seconds since Jan 1, 1970, 00:00 GMT
  printf( "t = %i\n", t);
  srand(t);

  for( int i = 0; i < 10; ++i)
  {
    // int r = rand(); printf( " %i", r); // raw values
    // int i = 1 + rand() % 10; printf( " %i", i); // integers in range 1 to 10
    double d = 10 + 5*(rand()/(double)RAND_MAX); printf(" %g", d); // range 10.0 to 15.0
  }

  printf("\n");

  return 0;
}

/* sample output:

t = 1644942348
 10.9434 14.6412 13.7712 10.8337 12.3085 12.7952 10.7465 13.6447 10.3362 13.1303

*/